deletions | additions       diff --git a/figures/fig_for_inclass_nova1/caption.tex b/figures/fig_for_inclass_nova1/caption.tex  index 37ffc6f..6805588 100644  --- a/figures/fig_for_inclass_nova1/caption.tex  +++ b/figures/fig_for_inclass_nova1/caption.tex 
...
\label{fig:inclass_lab}  Figure supporting an in-class exercise on understanding image values and signal-to-noise, carried out during the lab period. The exercise itself consisted of the following:  \itshape \textit{%  Consider the attached image of a nova observed with the millimeter telescope CARMA at 96 GHz (Panel A). Histograms of pixel values are shown in Panels B and C (Panel C is just a zoom-in of a region on Panel B); these are just like the histograms you made in DS9's \verb|Scale Parameters|. The pixel values after calibration are expressed as flux density per pixel (units of mJy/pixel). The plotted range ($-2$ to $36\,\mathrm{mJy/pixel}$) includes all pixels in the image. image.}  \noindent \emph{1) {1)  Estimate the average background value ($\bar{S}$) and explain your reasoning.}\\ \noindent \emph{2) Estimate the standard deviation of the background ($\sigma$), and explain your reasoning.}\\  \noindent \emph{3) Estimate the peak flux density of the nova ($S_{\rm max}$), and explain your reasoning.}\\  \noindent \emph{4) Astronomers usually only take detections seriously if they are 5 or more $\sigma$ significant---that is, if the detected source is at least five times brighter than the   standard deviation of the background. In other words, the source's peak flux should be $S_{\rm max} > (\bar{S} + 5 \sigma)$. Estimate how many sigma the peak flux density of the nova is, and show your reasoning. Would this detection be taken seriously by other astronomers?}\upshape